formula_raider Posted August 22, 2011 Share Posted August 22, 2011 I was wondering what the majority of the people have done on the wiring upgrades to their S30 cars when a LS engine swap was performed. Are you just adding an additional constant hot & switched fuse block to the existing stock wiring harness of the S30 or replaceing the whole wiring harness and fuse panel with a aftermarket unit from E-Z, Kwik wire or painless and completely rewiring the car? Just wondering if anyone is having problems with the stock wiring handling the increased amperage from the alternator of the LS-1 engines. I have done a complete re-wire on a vehicle before and although it is nice to have the extra circuits to run power windows, door locks, etc...it is a pretty big deal to do and if the stock wiring is sufficient with the correct add on fuse blocks/relays I would like to go that route. I like to know your thoughts and how they have been working for you. Thanks, Quote Link to comment Share on other sites More sharing options...
ktm Posted August 22, 2011 Share Posted August 22, 2011 When I first did my L28ET swap for my 240z, I used the stock harness for the dash and lights only. I made my own EFI harness as I wanted to eliminate the possibility of 40 year old wiring bugs causing me issues. I've since rewired the entire car following a small fire incident related to the stock harness I left in-place. The swap itself only requires around 8 wires. I would run a small supplementary circuit just for the swap. Even though I am now using a Painless fuse block, my LS1 swap utilizes a small secondary fuse block/circuit dedicated to it. Quote Link to comment Share on other sites More sharing options...
mpramsey Posted September 8, 2011 Share Posted September 8, 2011 I replaced the entire car wiring harness with that of a 2002 TransAM wiring harness. It took considerable effort to identify all the circuits but with wiring diagrams it can be done. I now have VATS enabled, Power accessories and a possible future modification to ABS and Traction control. I did have to replace the steering column, and fuel tank with that of the TransAm too. If anyone desires to do such as I have done make sure that the steering column includes the key and matching body control module or BCM. With the VATS system the BCM reads the key resistance chip then sends a signal allowing the starter solenoid and fuel pump to operate. Once started the PCM must read a passcode from the BCM to keep the fuel pump in operation. Its all complex but interesting to learn about. Quote Link to comment Share on other sites More sharing options...
VinhZXT Posted September 22, 2011 Share Posted September 22, 2011 The stock fuse block is fine. Just make sure you connect relays to feed power power to everything you added. The stock wiring harness caused so much problems because all the power wires are direct connections. Over time it built up corrosion. If you have relays in place it won't start the corrosion. I've done the swap on my friend's 280Z and I used the stock fuse block and he has not seen any problem after 5 or 6 years now. If you want to get fancy then go ahead replace all the wirings. Quote Link to comment Share on other sites More sharing options...
rsicard Posted September 22, 2011 Share Posted September 22, 2011 The stock fuse block is OK provided the connections that may be corroded are cleaned up. Additionally, the headlight circuit should have a relay added as this is a heavy current draw and more susceptible to bad connections and voltage drop. Any high current such as Alternator or Electric Radiator Fan should be wired with appropriate size wire, relays and fuses. Put a heavy fuse block in the engine compartment for the alternator heavy current feed to the battery. Same with the Electric Radiator Fan and add a relay for control of same. Running Lights, interior lights etc can be changed over to LED replacement bulbs which have a much lower current draw. Remove the turn signal and headlight stalk switches and carefully clean up lube the contacts with clear silicon grease. If all the former is done, then all should be good for many years to come. Quote Link to comment Share on other sites More sharing options...
Bigdeezs Posted September 30, 2011 Share Posted September 30, 2011 (edited) I mated my F-body engine harness to the the stock 280z harness for mine. I had the same issues with corrosion around the direct power connections but that had nothing to do with the swap. Also I tried using the stock 280z fuel pump power wire for the inline walboro pump as it looked to be about 10-12awg but for some reason the correct voltage just was just not making it to the pump. I ended up running a separate wire and have been issue free since. ...oh and also separate relays for the 2 speed taurus fan controlled by the f-body ecm. Edited September 30, 2011 by Bigdeezs Quote Link to comment Share on other sites More sharing options...
Lighft01 Posted October 17, 2011 Share Posted October 17, 2011 speartech harness for the engine/cpu, and painless for everything else on the car... expensive way to do it. If/when i do it again i would probably use a factory ls1 harness and mate it up with a painless. Quote Link to comment Share on other sites More sharing options...
master_339 Posted January 15, 2012 Share Posted January 15, 2012 For questions on a LT1/LT4, or LSx Swap for 240,260, or 280 z and zx Current Performance Wiring in New Port Richey, Fl can make stand alone harnesses for your application. You can call Jared at 727-844-7570 or visit currentperformance.com Orders ship domestically and internationally Quote Link to comment Share on other sites More sharing options...
RebekahsZ Posted January 15, 2012 Share Posted January 15, 2012 (edited) Ask the local guys at the drag strip in your area to see if there is a local guy who does it. I sent my harness off for a $450 modification and it came back all screwed up and the computer was reconfigured incorrectly. Asked the guys in the local AC Cobra replica club and found a guy 1 hour away who re-did it all for $250. This sort of service is becoming more and more accessible even here in po-dunk Alabama. PM me to find out who I used the first time so that I'm not critical of a business on the general forum, but I would not use them again. Edited January 15, 2012 by RebekahsZ Quote Link to comment Share on other sites More sharing options...
h4nsm0l3m4n Posted January 15, 2012 Share Posted January 15, 2012 (edited) Bit of an old thread but I figure I'll throw out my 2 cents. I bought a complete standalone harness from http://chevythunder.com/ It cost 450 and came with a flashed, ready to run, ECU. It came with all fuses and relays necessary to run the engine, all the transmission connections, tach/speedo/oil pressure ECU outputs for gauges, fuel pump relay, and (at my request) a high amp relay, fuses and wires to run my 2 speed Taurus fan. Lead time is a bit longer than Painless, for example, but I think this is because the seller builds each harness individually. He can, to a degree, actually customize the wire lengths based on where you decide to route the wiring and the final location of the ECU. Additionally he asks you to specify the connector types on some of the engine sensors (in case you a running later model engine, or a truck motor) to make sure everything is going to hook up right. All wires are, of course, labeled and the harness comes with a nice PDF detailing the installation procedure and included steps to correct a couple common problems people get along the way. Regarding installation, everything went perfectly. Once laid out the harness made it very obvious what connector goes where. Once I had it all hooked up the car started from the first turn of the switch (and still starts every time without issue 12000 miles later). For the price this is really a no brainer. It turned the most intimidating (and possibly the most time consuming) part of the swap into a simple 2 hour job.... Can you guys tell I'm pretty happy about how it turned out? Edited January 15, 2012 by h4nsm0l3m4n Quote Link to comment Share on other sites More sharing options...
rsicard Posted January 15, 2012 Share Posted January 15, 2012 h4nsm0l3m4n: Now that is a VERY GOOD referral for chevy thunder. It appears that those are the folks in San Antonio Texas. They have been around for quite some time. Looks as though they can be trusted for Gen I, II, III and IV harnesses and PCM reprogramming. Quote Link to comment Share on other sites More sharing options...
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